A Generalisation of the ICP Algorithm for Articulated Bodies

Abstract

The ICP algorithm has been extensively used in computer vision for regis-tration and tracking purposes. The original formulation of this method is restricted to the use of non-articulated models. A straightforward generali-sation to articulated structures is achievable through the joint minimisation of all the structure pose parameters, for example using Levenberg-Marquardt (LM) optimisation. However, in this approach the aligning transformation cannot be estimated in closed form, like in the original ICP, and the approach heavily suffers from local minima. To overcome this limitation, some au-thors have extended the straightforward generalisation at the cost of giving up some of the properties of ICP. In this paper, we present a generalisation of ICP to articulated structures, which preserves all the properties of the original algorithm. The key idea is to divide the articulated body into parts, which can be aligned rigidly in the way of the original ICP, with additional constraints to keep the articulated structure intact. Experiments show that our method reduces the residual registration error by a factor of ≈2. 1